CHRIS Christie’s gutsy win in New Jersey puts the arrogant big spender Jon Corzine in his place. But it is the election in Virginia that probably has more to say to marginal Democratic congressmen considering how to vote on health-care reform.

Obviously, Christie’s victory is a body blow to Obama after Corzine outspent the Republican by five-to-one and the president put on a serious push for the incumbent. Corzine’s defeat sends a message that the nation is moving sharply against Obama.

But Virginia results are the most important. More than 80 Democratic congressmen and 20 senators come from states that John McCain carried in 2008. For them, the sudden switch in Virginia, a swing state that Obama actually carried, heralds tough political times ahead.

New Jersey is the quintessential blue state. If it goes Republican, blue state congressmen needn’t worry. Their districts are likely still safe. But when a Republican in Virginia wins by 20 points, it sends a message to red-state Democratic congressmen to take cover.

Polls indicate a declining level of popular approval of the Obama policies (Rasmussen shows his job approval at 46 percent), but to see actual Democrats losing or barely squeaking out victories in solidly blue states sends a far clearer message to the Democrats in Congress.

Until last night, Democratic moderates, the so-called blue dogs, could bask in the light of their candidate’s success in 2008. But now they must hear hoof beats behind them. The party discipline on which Obama depends to pass a health-care program that Americans reject by 42 percent for, 55 percent against (Rasmussen again) will only work if beleaguered Democratic incumbents can wrap themselves in Obama’s cloak and tough out the popular criticism. But the limits of Obama’s drawing power are readily apparent in the Republicans’ 20-point victory in Virginia and the race in New Jersey.

In the coming weeks, House Speaker Nancy Pelosi and Senate Majority Leader Harry Reid will be asking their troops to cast potentially career-ending votes for health-care changes, Medicare cuts, higher taxes and fines on the uninsured. Whether they take that risk depends on their faith in Obama’s drawing power.

But the votes in Virginia, in particular, show the limits of Obama’s appeal. The winner, Bob McDonnell, won the attorney general’s race in the last election by a few tenths of a percent over the same opponent. That he coasted to so huge a victory in the swing state of Virginia now has to send a message to red-state Democratic congressmen: Obama may be able to survive in the deep water into which he is leading his party, but you can’t.